What to record about the floor before replacing a vanity

A vanity replacement needs a floor record that describes more than the room's width. The selected cabinet may stand on different points, expose a previously hidden patch or sit across a change in elevation. Record those conditions before approving the cabinet and its finished height. The purpose is to give the installer useful observations; choosing a correction or support method belongs to the selected product and the actual site assessment.

Mark where the new cabinet will bear

Place the proposed footprint on a plan and identify its actual support arrangement from the product information. Furniture-style feet, a continuous base and other constructions do not touch the floor in the same places. A floor observation taken in the middle of the room may say little about the locations that will support the new vanity.

Show the existing vanity outline on the same plan. If part of the new footprint remains hidden, mark it as unobserved rather than describing it as satisfactory. Include any floor-entry pipes or other obstacles. Decide with the project team when concealed areas can be inspected and which purchasing decisions depend on that inspection. Avoid treating a measurement of the old cabinet as proof of the floor beneath it.

Separate flatness from level

A surface can be flat yet slope, and it can have localized high or low spots even when broad measurements look level. Those are different observations. Record the method and locations used by the installer or measuring professional, together with the reference from which heights are compared. Do not combine readings taken from changing reference points into a single floor profile.

For a hypothetical survey, suppose the floor at the proposed left-front support is 10 inches below a fixed horizontal reference. At the right-front support it is 10.5 inches below that same reference. The right location is therefore 0.5 inch lower. This explains the reading only; it does not prescribe a shim, an adjustable-foot setting or a permissible difference for any cabinet.

Identify which floor is the finished floor

Record whether existing tile or another finish continues beneath the old vanity. If new flooring is planned, name the surface used for the current survey and the one expected at completion. The cabinet's finished position, basin rim and adjacent trim will be coordinated with the completed floor, so an unclear floor reference can spread into several other decisions.

Keep edge conditions visible as well. A new foot or recessed base may reveal a patch that the old plinth concealed. That is a finish-scope question, separate from whether the floor can support the cabinet. Do not choose a larger cabinet simply to hide an area until its support, circulation and fixture relationships have also been checked.

Let the installation requirements guide the response

Give the observations to the installer alongside the selected product instructions. Some cabinets have specific requirements for the supporting surfaces and attachment. The cited Kohler guide is an example of a manufacturer addressing floor and wall conditions; its instructions should not be transferred to a different vanity.

Reading note: Kohler: Vanity installation and care guide.

Ask the project team to identify what condition must be achieved, who will handle the necessary floor work and when it will be checked. Do not specify a stack of loose packing pieces or alter a cabinet base from a general article. If the floor condition raises a larger building concern, resolve that with the appropriate professional before treating cabinet installation as the solution.

Check the effect on the finished assembly

Any approved change to the cabinet's installed elevation should be carried into the basin, mirror, backsplash and plumbing review. Compare the result with the people using the bathroom. Raising one part of an assembly without reviewing the rest can leave a different wash position from the one approved during selection.

Keep the marked support locations, photographs, height observations and completed-floor description together. Add the installer’s confirmed response when available. Recheck after floor work and before the top position becomes final. A useful survey leaves a clear record of what was seen, what remained concealed and how the selected vanity's position was ultimately established.